At present, the pipeline materials used in automobile can be divided into three categories: nylon pipe, rubber pipe and metal pipe. The commonly used nylon tubes are mainly PA6, PA11 and PA12. These three materials are collectively referred to as aliphatic Pa. PA6 and PA12 are ring opening polymerization and PA11 is condensation polymerization.
1. The advantages of nylon pipe are as follows: ▼ excellent oil resistance (gasoline, diesel), lubricating oil and grease, and chemical resistance. ▼ low temperature impact resistance: PA11 can withstand low temperature impact of – 50 ℃ and PA12 can withstand low temperature impact of – 40 ℃. ▼ wide application temperature range: the application temperature range of PA11 is – 40 ~ 125 ℃, and the position of PA12 is – 40 ~ 105 ℃. After aging test at 125 ℃, 1000h, 150 ℃ and 16h, PA11 pipe has good low-temperature impact performance. ▼ resistance to oxygen and zinc salt corrosion: resistance to 50% zinc chloride solution for more than 200H. ▼ resistant to battery acid and ozone. ▼ it is a self-lubricating material with vibration resistance, wear resistance, fatigue resistance and low friction coefficient. ▼ UV resistance and atmospheric aging: the UV resistance of natural color PA11 can be used for 2.3-7.6 years depending on different regions; The anti ultraviolet ability of black PA11 increased by four times after adding anti ultraviolet absorbent.
The processing procedure of nylon pipe is: ① extrusion procedure ② forming procedure ③ assembly procedure ④ detection procedure. In general, nylon pipe has great advantages in performance compared with metal pipe, while it is better in chemical corrosion resistance and wear resistance compared with stainless steel pipe, which plays a great role in reducing vehicle weight and production cost.
2. There are many rubber hose structures for automobile, and the basic structures include ordinary type, reinforced type and coated type.
Basic structure of rubber hose at present, the most used rubber pipe materials in the market are FKM, NBR, Cr, CSM and eco: ▼ the service temperature of FKM (fluororubber) is 20 ~ 250 ℃, which is mainly used for O-ring, oil seal, inner layer of fuel hose and other sealing products. ▼ the service temperature of NBR (nitrile rubber) is 30 ~ 100 ℃, which is mainly used for rubber hose, sealing ring and oil seal. ▼ the service temperature of Cr (chloroprene rubber) is 45 ~ 100 ℃, which is mainly used for tape, hose, wire coating, rubber plate gasket ‘dust cover, etc. ▼ the service temperature of CSM (chlorosulfonated polyethylene rubber) is 20 ~ 120 ℃, which is mainly used for tires, tape, spark plug sheath, wires, electrical parts, O-rings, door and window sealing strips, etc. ▼ the service temperature of eco (Chloroether rubber) is 40 ~ 140 ℃, which is mainly used for hot ring, diaphragm, shock pad, rubber hose, etc.
3. As a kind of hard pipe, metal pipe has the advantages of heavy weight, high cost and easy fracture. Therefore, more and more vehicle enterprises choose to give up the use of metal pipe. At present, metal aluminum pipe is more suitable for air conditioning system. However, the tensile strength, bursting pressure and aging resistance of metal pipes are better than those of nylon pipes and rubber pipes.
Post time: May-24-2022